1. Field of the Invention
The present invention relates to a center cluster assembling structure in which a plurality of electrical devices disposed nearly centrally in a transverse direction of a vehicular instrument panel, such as an audio unit, a display unit, a navigation unit, and an air-conditioning operating unit, are clustered as an integral structure. In addition, the present invention relates to an electrical connection structure of the electrical devices.
2. Description of Related Art
As shown in FIGS. 11A, 11B, a center cluster 101 is constructed by an audio unit 140 and an air-conditioning operating unit 180 which are disposed centrally in a transverse direction (width direction) of a vehicular instrument panel.
In the audio unit 140, switch portions (not shown) of operating members 140S for operating the audio unit 140, a CD deck 142, and a main electrical circuit substrate 161 are fixed within a case 107 by clamping means such as screws. Brackets 108 mounted sideways of the case 107 are clamped respectively to instrument panel-side mounting members 109 by bolts 108a to hold the audio unit 140 in the vehicular instrument panel.
The case 107 includes a case body 107a which is formed into a box shape using a sheet metal, an ornamental panel 107b made of resin and covering an opening of the case body 107a, opened toward an inside of a passenger compartment, and a heat radiating fin 107c which contacts a power IC 161a formed on the main electrical circuit substrate 161 and which functions to radiate heat from the power IC 161a. The operating members 140S having the switch portions are disposed so as to be exposed directly into the passenger compartment from apertures formed in the ornament panel 107b. The ornamental panel 107b and the heat radiating fin 107c are fastened to the case body 107a using screws 107d from both side and rear portions of the case body 107a. 
Also, in the air-conditioning operating unit 180, similarly to the audio unit 140, a case 107 which incorporates therein switch portions (not shown) of operating members 180S and a main substrate (not shown) is clamped to the instrument panel-side mounting members 109 through brackets 108. One or more connectors 106a of one or more vehicle-side wire harnesses 106 on the vehicle front side are connected to center cluster 101.
A frame-shaped front panel 110 is fitted on outer edges of the cases 107 of the audio unit 140 and the air-conditioning operating unit 180 from the inside of the passenger compartment so that the brackets 108 and the like are hidden from the interior of the passenger compartment.
However, in a case where the CD deck 142 or the substrate 161 are to be taken out from the center cluster 101 into the passenger compartment, when an attempt is made to remove the ornamental panel 107b from the case body 107a, the air-conditioning operating unit 180 is an obstacle to removal of the ornamental panel 107b because it is disposed just above the screws 107d. 
Therefore, in a state where the case body 107a is fixed to the instrument panel, it is impossible to remove the CD deck 142 and the main electrical circuit substrate 161 from the inside of the passenger compartment. Unless the case 107 is once taken out into the passenger compartment and is disassembled, it is impossible to take out the CD deck 142 and the main electrical circuit substrate 161 from the interior of the case 107 into the passenger compartment.
More particularly, for taking out the CD deck 142 and the main electrical circuit substrate 161 from the center cluster 101 into the passenger compartment, first the ornamental panel 110 is removed and the case 107 is removed from the instrument panel-side mounting members 109, then the ornamental panel 107b or the heat radiating fin 107c is removed from the case body 108a, and thereafter the CD deck 142 and the main electrical circuit substrate 161 are removed from the case body 107a. 
Thus, even when only the CD deck 142 or the main substrate 161 is to be taken out into the passenger compartment, it is required to once take out the whole of the audio unit 140 into the passenger compartment. Such a manual work for removing the whole of the audio unit 140 which is heavy has been a heavy labor. Besides, an additional work is needed for disassembling the case 107 into the case body 107a, the ornamental panel 107b and the heat radiating fin 107c. Thus, the operation for removing the CD deck 142 and the substrate 161 is made to be complicated.
In view of the foregoing problems, it is an object of the present invention to provide a center cluster assembling structure which facilitates operation for removing such electrical devices of a vehicular center cluster as a CD deck and a main electrical circuit substrate.
It is an another object of the present invention to provide an electrical connection structure of plural electrical devices of a vehicle center cluster, which improves electrical connection operation and electrical removing operation between the electrical devices and a wire harness.
According to the present invention, in an assembling structure of a center cluster disposed inside a dashboard of a vehicle at an approximate center portion in a vehicle right-left direction, electrical devices are assembled to a holding member to be respectively detachable from an inside of a passenger compartment of the vehicle while the holding member is fixed to the dashboard. Therefore, when one of the electrical devices (e.g., a deck) is removed from the center cluster, only the one of the electrical devices can be detached from the holding member without detaching the other electrical devices, in a state where the holding member is fixed to the dashboard. Further, when the center cluster is assembled to the vehicle, first, the holding member is fixed to the dashboard from the inside of the passenger compartment, and then the electrical devices are respectively assembled to the holding member from the inside of the passenger compartment. As a result, any one of the electrical devices can be readily removed from the passenger compartment, and removing operation of the electrical device can be made simple.
Preferably, the electrical deck and the electrical circuit substrate are disposed to be stacked in a vertical direction. Therefore, the electrical deck and the electrical circuit substrate can be readily removed from the passenger compartment, among the electrical devices.
More preferably, the electrical devices have front side surfaces opposite to the inside of the passenger compartment in a vehicle front-rear direction, the front side surfaces of the electrical devices have engagement portions, respectively, being detachably engaged with engagement portions of the holding member, and at least one of the engagement portions of the electrical devices and the engagements of the holding member is elastically deformed while being engaged. Therefore, the electrical devices and the holding member can be fitted by an elastic deformation. Accordingly, the electrical devices can be readily detachably assembled to the holding member fixed to the dashboard.
On the other hand, in an electrical connection structure of the vehicle center cluster, a wire harness for supplying electrical power to the electrical devices is electrically connected to one electrical device through a connection portion disposed at a vehicle rear side position of the one electrical device, and an ornamental panel is disposed at a vehicle rear side of the connection portion and the electrical devices and is assembled to be detachable from the inside of the passenger compartment. Accordingly, the electrical devices, the wire harness and the connection portion can be covered by the ornamental panel to be prevented from being exposed into the passenger compartment. Further, because the connection portion is disposed at the vehicle rear side of the one electrical device, the wire harness can be readily connected to or removed from the electrical device from the passenger compartment when the ornamental panel is removed from the passenger compartment. As a result, electrical connection operation and electrical removing operation between the wire harness and the electrical device can be readily accurately performed.
Further, an operating circuit substrate having an operating member is provided at a vehicle rear side of the electrical devices to operate the electrical devices from the inside of the passenger compartment, the electrical devices are electrically connected to the operating circuit substrate, and the electrical devices are electrically connected from each other through a printed circuit on the operating circuit substrate. Therefore, the electrical connection structure of the electrical devices of the center cluster can be made simple. Accordingly, assembling operation of the center cluster on the vehicle and removing operation of the center cluster from the vehicle can be made easy, with the simple electrical connection of the electrical devices.